The invention relates to a subgingival jaw implant with a metal anchor body on which a tooth replacement support can be supported.
Such a jaw implant is known from EP 0 747 017 A2. There, a cylindrical anchor body which can be screwed into the jawbone has, at one end, a surface with a raised hexagon profile. A threaded bore is provided in the hexagon profile. Supported on the surface there is a tooth replacement support, which is secured by means of a compression anchor screw which engages in the threaded bore. The tooth replacement support has a surrounding flange, on the upper side of which there bears the lower edge of a tooth crown received thereon.
The known jaw implant has the disadvantage that the anchor body can come loose in the bone even in the event of a light impact on the tooth crown. A further disadvantage is that a gingival pocket forming around the screwed-in anchor body does not have an optimum shape from the periodontal point of view. In particular, no papilla, or ginigival elevation, is formed in the interspace between the implanted tooth and the healthy tooth. As a result, the adjacent healthy tooth is susceptible to periodontitis.
EP 0 111 134 A1 further discloses a transgingival jaw implant with an anchor body made of ceramic material. During the incorporation phase, the anchor body of this implant penetrates the gingival epithelium, which settles on a radially surrounding groove of the anchor body. The protruding anchor stump is uncomfortable for the patient. Due to constant mechanical stresses acting on the anchor stump during incorporation, the direct one fusion with the surface of the anchor body, which is absolutely essential for an optimum hold, does not take place, i.e. there is no osseointegration. Here, the implant becomes incorporated in the bone by the agency of a layer of connective tissue. The layer of connective tissue has the disadvantage that it allows infections to enter. Because of the brittleness of the ceramic material, it is not possible to fix a tooth replacement support by means of a screw. The tooth replacement support has to be cemented onto the anchor body. This makes it difficult to repair such a jaw implant. Moreover, in the event of an impact on the tooth replacement, the anchor body may break. Changing a broken anchor body is expensive.